Wind Generation Integration NERC MRC Meeting May 6, 2008 Warren Frost Vice President, Operations and Reliability Wind Generation Integration NERC MRC Meeting May 6, 2008 Jim McIntosh Director, Grid Operations

Overview What are the operational issues? What are the impacts and what should we pay attention to? What are potential solutions? Forecasting and Operator tools Backstop generation Wind Power Limiting/Curtailment Interties (subject to rules/standards) Storage Demand side Transmission We must maintain reliability

Operational Issues - AESO Output can be counter to load ramps or faster than the system ramp Unpredictable patterns – operators need to consider wind variability and prevent large imbalances from occurring Low capacity factor – can be zero at times of peak Variability during disturbances or restoration efforts – may not be tolerated Voltage Issues – new wind technologies will meet reliability requirements including LVRT and reactive support May create oversupply conditions

Wind generation tends to be inversely correlated to daily load curve, creating ramping impacts - CAISO

Typical Oversupply Conditions - CAISO Light load conditions – loads around 22,000 MW or less, All the nuclear plants on-line and at maximum production, Hydro generation at high production levels due to rapid snow melt in the mountains, Long start thermal units on line and operating at their Pmin levels because they are required for future operating hours, Other generation in a “Must Take” status or required for local reliability reasons, and Wind generation at high production levels. Imbalance between Generation and Load

Tehachapi Wind Generation in April – 2005 Could you predict the energy production for this wind park either day-ahead or 5 hours in advance? 700 Each Day is a different color. 600 Day 29 500 Day 9 400 Day 5 Megawatts Day 26 300 Average 200 100 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 -100 Hour

Wind generation output changes quickly – diversity? Total California Wind Generation 200 400 600 800 1000 1200 0:01 1:01 2:01 3:01 4:01 5:01 6:01 7:01 8:01 9:01 10:01 11:01 12:01 13:01 14:01 15:01 16:01 17:01 18:01 19:01 20:01 21:01 22:01 23:01 MW TOTAL Pacheco Solano Tehachapi Altamont San Gorgonio

Wind generation output changes quickly – diversity? SW SC SE North South West (SW) = 212.3 MW South Central (SC) = 176.2 MW South East (SE) = 110.0 MW

Limits to Dispatchable Resources - AESO 12000 Off-Line Generation (Maint or Economics) 10000 Ancillary Services 8000 Dispatchable Generation MW Capacity 6000 4000 Non-Dispatchable Generation 2000 2006 Data 2weeks per division

Wind Power Management - Ramping Events When forecasts miss an event, the only available resources for the operator are dispatchable resources and Wind Power Management If there are insufficient resources to handle the ramps, power limiting would be used Potential curtailment of wind with 150 MW power limit Day ahead forecasts miss the event 2 hour ahead forecast missed the event

AESO Approach to Wind Integration Challenges Solutions Predictability of wind power Wind power forecasting rules and requirements Backup generation for wind power Energy Market, Regulating Reserves, Wind Following Wind variability, supply surplus, ramping events Wind power management, forecasting & OPPs Transmission development Credible forecasts of wind project development Wind interconnection projects Queue management Load Transmission and ancillary services Wind Facility Owners Forecasting and Power management Cost Allocation

CAISO Approach to Wind Integration New wind generators participate in CAISO PIRP program, with centralized day-ahead and hour-ahead forecasting service New market design is implemented Hour-ahead load and wind generation energy forecasts provided no less than 120-minutes before beginning of next operating hour Real Time five-minute load forecasts provided 7.5 minutes before beginning of five-minute dispatch interval Real Time telemetry from wind resources sent to CAISO on a four-second basis, similar to non-intermittent resources Technical requirements for new wind plants (LVRT & Power Factor) Pump storage considered a scheduled resource

Intra-hour load following is manageable - CAISO Load following is necessary to maintain stable operations. The CAISO’s Real Time Market balances Load and Generation on a forward looking basis While some generators are dispatched upwards to meet their next hour schedules other generators may have to be moved downwards to maintain a generation load balance Real Time Economic Dispatch software runs every 5-minutes and dispatches generation based on economics and ramping capability Load following ramping requirements will increase and require more generation to be available for both upward (700-800 MW) and downward (600-1,000 MW) dispatch.

Additional regulation requirements are significant but manageable - CAISO Regulation is required for the CAISO to maintain scheduled frequency and maintain schedules on the interties Today, the CAISO can effectively operate the system by procuring ± 350 MW of regulation on an hourly basis By the 20% RPS built-out, regulation capacity requirements will increase by 170-250 MW for “up regulation” and 100-500 MW for “down regulation” depending on the season and time of day.

Operators Need Info - What is Changing? How good is the load forecast today? What are the Interconnection schedules? What is the load forecast change? What is the ramp rate? What generators are still ramping from the last dispatch? How much energy is still to come? Is the merit order changing? How good is the wind power forecast today? What is the wind power forecast? What is the ramp rate?

Operators Need to Tools to make supply-demand balancing decisions What is the ramp rate capability in the merit order over the next 10, 20, 30 minutes? What are the Regulating Reserve units doing? How much capacity to dispatch to get the required ramp rate? Do I need to dispatch more ancillary services? Will I need to activate any WPM procedures? Will I need to activate Supply Surplus / Shortfall procedures?

Repeat When Necessary

Transmission system analysis accounts for existing and new wind installations. The CEC predicts that about 4,600 MW of new wind generation to meet 20% RPS. The CAISO study assumes the new generation is installed in the Solano and Tehachapi wind areas based on projects in the transmission queue and approved transmission upgrades. The CAISO study accounts for about 2,600 MW of existing wind generation. Shasta Lassen Solano County Altamont Pass Tehachapi & Mojave Desert Pacheco Pass San Gorgonio Pass Salton Sea Imperial Valley

3,300 MW of wind ~ 750 $ M of Transmission in Alberta

Storage Technology could facilitate renewables Pump Storage 3rd pump at Helms will integrate large amounts of wind generation. Requires upgrade of infrastructure to Fresno area Potential construction of Leaps Project Hydrogen Storage Evaluate hydrogen storage – recommend visit to DOE sponsored hydrogen storage project in Colorado Compressed Air Storage Battery Storage High Speed Flywheel Storage Develop strategy for financing and implementing storage systems

4 Types of Demand Response Programs Price Sensitive load that is willing to reduce demand for the right price. Demand that is bid into Day-Ahead markets to reduce peak load Interruptible Load – Loads that are willing to be interrupted or curtailed under emergency conditions – Stage 2 Emergencies – and will immediately take action in response to a dispatch notice. Frequency sensitive load – Load that is willing to turn off or reduce consumption due to a drop in system frequency. Example is Plug-In Hybrid Vehicles that will automatically stop charging their batteries when the frequency is low. Load that is willing to change based on availability of excess wind generation production

Summary - Impacts/Implications Must understand the reliability and planning implications of Policy Initiatives, Legislation and Renewable Portfolio Standards Need sophisticated wind forecasting tools Need conventional generation – wind needs a dance partner Need wind power management Operators need to know what to do and have the resources, tools and operating procedures Need Major Transmission Upgrades WPF must meet technical requirements (SCADA, voice, LVRT, reactive power) Storage and Demand technologies/options can assist

Operational challenges must be resolved 2007 LTRA Report Integration of Wind & Solar Resources Require Special Considerations in Planning, Design, & Operation Operational challenges must be resolved Transmission needed to support renewable development “Clean Energy Superhighway”

NERC Actions Evaluate operational requirements Recommend standards. Develop a consistent approach for rating variable resources Available capacity at time of system peak Initiate Integration of Variable Generation Task Force

IVGTF Scope The Task Force will prepare The document will include: A concepts document that includes the philosophical and technical considerations for integrating variable resources Specific recommendations for practices and requirements, including reliability standards, that cover the planning, operations planning, and real-time operating timeframes. The document will include: Planning timeframe issues, such as contribution to reserve margins and modeling requirements to test system reliability, Operational Planning and Real-time operating timeframe issues, including Interconnection frequency, and primary and secondary generation control Review NERC Standards for any gaps Conclusions and recommendations.

Guiding Principles for IVGTF Report Bulk power system reliability must be maintained, regardless of the generation mix All generation must contribute to overall bulk power system reliability Standards and criteria established must be fair, transparent and performance-based Planners and operators must understand the challenges presented by large scale integration of variable generation Wind and other variable generation must effectively integrate into planning and operations practices to ensure reliability New Planning/operating tool requirements will be described in terms of bulk power system reliability performance

Outline of IVGTF Report- Team Leads Introduction Mark Lauby (NERC) Characteristics of Variable Generation Dariush Shirmohammadi (Consultant) Planning and Technical Impacts Daniel Brooks (EPRI) System Operations John Kehler (AESO) Other and Future Considerations Charlie Smith (UWIG) NERC Standard Review Conclusions & Recommendations Glossary

IVGTF Status High Industry Interest Over 40 members Liaisons being built with Industry Groups American Wind Energy Association (AWEA) Canadian Wind Energy Association (CanWEA) Utility Wind Integration Group (UWIG) Solar Energy Industries Association (SEIA) IEEE-PES EPRI U.S. Department of Energy Union for the Co-ordination of Transmission of Electricity (UCTE)

IVGTF Status: Work Plan Item Goal Lead 2008 Milestones Conf. Call Review Report outline & assignments Lauby February OC/PC Status Report Frost & Lauby March Conf Call Review assignments first drafts Task Force Meeting Review Second drafts May Status Report & preliminary findings June Review Final Draft Report August Present Final Draft Report Capacity Method Recommendations September Review OC/PC Comments & develop Final Report Present Final Report and recommendations December Meeting/ Workshop Open Meeting to Present results Early 2009

Summary We are learning as we go We need to educate Need to share acquired knowledge We need to educate The public, ourselves, policy makers and many new players to the industry We must simplify the messages Our dads/grandfathers remember windmills and back-up on the farm We must maintain reliability